In a statement, Reznor and Ross explained the following of their Bird Box score:

We created a significant amount of music and conceptual sound for Bird Box, a lot of which never made it to your ears in the final version of the film. We've decided to present you with this version of the soundtrack record that represents what Bird Box is to us. We hope you enjoy.

For those interested, we will be releasing a more expansive (read: more self-indulgent) physical-only offering this spring that will contain an additional hour of music and artwork that colors further outside the lines.... Enter at your own risk!

As you will notice, the streaming version of Bird Box is an "abridged" version of the soundtrack. That's because, as previously reported, the score for director Susanne Bier's film will also be treated to "a more expansive" physical version this spring. It will feature an additional hour of music and "artwork that colours further outside the lines."